Time fuse



Patented May l, 1923.

UNE'EU TATES ALTEN s. MILLER, or BALTIMORE, MAItYLann.

TIME rusia.

Application led September 28, 1917, Serial No. 193,690. Renewed November27,v 1922.

T 0 all whom t may concern citizen of the United States, residing atBaltimore, in the Sta-te of Maryland, havev invented certain new anduseful improvements in Time Fuses, of which the following is aspecication.

This invention relates to improvements in time fuses lfor shells,projectiles, bombs, grenades or the like, and has particular referenceto a fusey that is designed todo the particular work for which it isintended at a predetermined time after being set in operation.

As heretofore constructed, fuses employing time powder trains vary intheir time of burning according to the variations in pressure of theexternal atmosphere. For' this reason variations in the time of burningoccur if the fuses are employed in mountainous regions, or in highaltitudes, as when used in anti-aircraft shells, and the operationsdesired are often delayed until comparatively long periods after thetime the fuse has been set to operate, or to effect an explosion, withthe result that they are ineffective of the desired result.

These inaccuracies in the time of burning are due to the fact that thehigher the altitude in which the fuse is used the less will be thepressure under which the powdertrain must burn, and the slower will theburning be. Consequently, if the time rings, in the case of a shell, areadjusted to effect an explosion at the termination of a given number ofseconds, and the shell then fired into the air to a considerablealtitude, the higher the shell is projected, the slower will 'the powdertrain burn, and the explosion, in the case of a shell, will not takeplace at the end of the predetermined number of seconds indicated by thetime rings.

By means of my invention, I overcome these serious objections byproviding a time fuse in which I maintain a substantially uniforminternal pressure on the burning powder train irrespective of theexternal atmospheric pressures, with'the result that the operation to beproduced by the burning powder train, will take place at the timedesired.

One object therefore of the present invention is to provide a fusehaving a timepowder-train with means to cause said train to burn at anapproximately uniform rate of soeed, irrespective of a wide range ofvariations in external atmospheric pressure.

Another object of the invention is topro- 'vide means whereby tomaintain a practically uniform internal pressure on the timepowder-trainregardless of a materially lesser externalv atmospheric pressure.

Another object is to construct a time fuse in an improved way to ventthe gases and relieve the internal pressure caused by the burningpowder-train, after those pressures have reached a predetermined point.

A still further object of the invention is to combine in a fuseemploying av time-powder-train, a vent and an improved automaticpressure-equalizing means operating between the powder-train and vent,to permit the escape of the excess pressure in the form of gasesgenerated by the burning powder and maintain a more nearly uniformpressure condition on the powder-train, whereby to cause the powder toburn at a substantially predetermined rate of speed.

vWith these, and other objects in view, a. form of structure forcarrying the inventive idea into practical effect is disclosed, it beingunderstood however that the invention is not to be restricted to theform or structure shown.

In the drawing:

Fig. l, shows the improved fuse located in a shell of shrapnelform,-.the parts being illustrated in vertical longitudinal section, andf Fig. 2, illustrates a modified form of pressure controllingdevice,-also in vertical section.

The inventive idea of my time fuse may find expression in various forms,and the same may be embodied in various kinds of shells, projectiles,bombs, grenades or like devices, so that the present illustrationshowing the fuse in a shrapnel shell, is in no way to be construed asdefining the structure or the scope or Ause of the invention.- 1

v Referring to the embodimentof the invention shown in Fig. 1, of thedrawing, the numeral 5, designates a shell casing of the shrapnel type,provided at the forward end with a suitable plug '6, whichlattenis:provided with a chamber?,v and -which also has passages 8, leadingtherefrom, which passages communicate with the time-powdervtrain grooves9, and 10, in the time-rings 11 and 12, respectively.

A suitable plunger device 13, is located at the outer end of the plug 6,by means of which and upon the shock of liring, ignition of thepowder-train in the groove l0, will take place to start the timingoperation.

All of'the above designated devices are old and well known, and ltheirbrief mention here is believed to be sufficient to aid in the disclosureot the present invention.

Beyond the plug 6, the shell has a metal capA 14, and channels 15,extending therethrough,-the inner ends of these channels being incommunication with the time-train grooves in the time-rings, whereby tovent the latter of gases generated by the burning powder-train While theshell is in Hight. These vent channels have heretofore been provided tovent the gases generated by the powder train in the shell, said gasespassing through vent apertures 16, that have been provided in the nose17, ot' said shell.

Various means may be employed in the i'use to maintain a uniforminterna-l pressure on the powder train, as will be seen lrom the presentdisclosures, but in the form of structure disclosed in Fig. 1, Iinterpose a valve device between the vent channels 15, and the externalvent apertures 16, which valve will remain seated until a predeterminedpressure on the channel side is reached, whereupon it will unseat andallow gas to escape and so prevent an excess pressure in the channelsand on the time train.

In the form of structure disclosed in Fig. 1, which, as stated, isintended for illustrative purposes only and not in any way as definingthe scope of' the invention, I provide a cavity 18, in which the outerends of the channels 15, terminate, and the outlet from said cavity iscontrolled by a valve structure 19.

In the present instance the valve 19, has the form of a puppet valve inthat it has an annular ange 20, that seats around the cavity 18, and isguided in its movement toward or from the seat by means of guide vpins21, which prevent lateral displacement of the valve during the shock oftiring or while the projectile in which the fuse is located is in light.The valve, in this instance, is of a conical form withits apexprojecting toward the! nose-end of the shell.

The nose-end ofthe shell is provided with a conical casing 17, theinteriorbase-end of which is rigidly attached to anrinternally-threadedbushing 22, that has threaded engagement with the body 14.

AOnthe interior of the nose casing 17, I

'provide a pressure receptacle 23, which, in

this instance, has the form of ademe whereby -to produce avchamber 24,Afor a-purpose 'presently to be explained.v This pressure re'- eeptacle,in this instance, has an annular lange 25, around the base of rthe dome,which flanger is provided with a plurality of ports 26, and the extremeend portion 2l', of the flange is formed into a ring-shape and hasthreaded engagement with, the bushing 22, whereby to secure the same in:an encircling position with respect to the valve 19.

The purpose of the pressure receptacle is to provide means that is notaffected by external atmospheric pressures, tor exerting a predeterminedpressure on the upper side ot' the vvalve 19, whereby to keep the valveyieldingly pressed to its seat, but which will permit the valve tounseat when the pressure on the lower side exceeds that on the upperside, and in this way will maintain a substantial equalization ofpressures on the opposite sides of thevalve.

In the present instance, the means employed in the pressure receptacleto transmit the desired pressure, is a diaphragm 28, which extendsacross the base of the dome and closes the bottom ot the dome-chamber211, and on the upper side of this dia} 3hragm and confined in thechamber is a fluid, such as air or gas. ThisV fluid-pressure in thedome-chamber exerts a constant predetermined pressure on the upper sideof the diaphragm and keeps the latter pressed down on top o'l the valve19, whereby to normally keep the latter seated over the chamber 18, andthe outer ends of the vent-channels 15. Ot course, in practice therelative areas of the valve and diaphragni are such that no matter whatthe atmospheric pressure on the exterior of the shell or on thefinteriorof the nose casing 1T, and fuse may be, the valve 19, will be keptseated by the pressure exerted by the pressure-means in the chamber 24,until the pressure inV chamber 18, and passagesvl, overcomes that inchamber 24, at which moment valve 19, will unseat and allow the excesspressure from the channels and on the time powder train to vent.

In the device illustrated in Fig. of the drawing, the fuse structure issubstantially the same as that disclosed in Fig. 1, in that it employsthe channels 15, plunger 13. and valve 19, but the pressure meansemployed for keeping the valve seated at a predetermined pressure isslightly modified.

In this modified form, the pressure receptacle has a. cylinder 29, witha piston headBO, snugly fitting and closing the lower end thereof, anda. spring 31, is located in the cylinder and exerts the desired pressureonv the upper side of the piston,-head. The lower side of thepiston-head seats on the upper end ofthe `valve 19, and holds the latterdown on its seat whereby to confine the gases in the passages 15, untilthepredetermined pressure is reached, whereupon the valve lifts to ventthe excess gases. l

In this instance a, vacuum Should be formed in the cylinder 29, and ontop of the pistonf-provision being made at 32, in the top of thecylinder for the exhaust of the air.

In this modified form the pressure receptacle may have the samearrangement o flanges 25, and 27, and vent ports 26, as are shown in thedevice of Fig. l.

In both forms of devices. shown, I provide a locking pin 33, whichextends through the wall of the nose-casing 17; the bushing 22, and theFlange portion 27, of the dome which effectively locks said partstogether.

Having described my invention what I claim is,-

l. In a time fuse, the combination with an exterior case, of a. timepowder-train on the interior of the case; valve means in the case on theescape side or' the powder-train; valveseating means one side or' whichis operatively connected to the valve to seat the latter and a housinghaving a sealed chamber to the interior of which the opposite side ofthe valve-seating means is exposed.

2. The combination with a case, of a time powder-train in the case;valve-means also in the case on the escape side of the powder train; ahousing in the case and having a chamber therein and avalve-closingdevice sealing said chamber and said closing deviceexerting a seating pressure on the valve.

3. In a time fuse the combination with an exterior case, of a timepowder-train on the interior of the case, valve means in the case andmovable in one direction topermit the gases generated by the burningpowder train to escape from the case said valve means being held to itsseat by a movable device one side of which movable device is exposed toa chamber that is sealed against atmospheric pressure.

l. In a time fuse thel combination with an exterior case, of a timepowder-train on the interior of the case, valve means in thecase andmovable in o-ne direction to permit the gases generated by the burningpowder train to escape from the case, a yielding device normallypressing the valve in a direction to close the same said yielding devicehaving one side exposed to a sealed chamber toward which the valve movesto e'ect a venting of the generated gases.

5. In a time fuse the combination with an exterior case, of a timepowder-train on thev interior of the case, valve means inthe case andmovable inone direction to permit the gases generated by the burningpowder train to escape from the case, a receptacle in the same case witha movable device therein to close the same said movablereceptacleclosing device engaging the valve means to n press the sametoward its seat and said receptacle being sealed against atmosphericpressure. Y

6. A time fuse having a vent from the interior to the exterior, incombination with a. time powder train, and means between said vent andthe time powdertrain for maintaining a uniform interior pressure on thepowder train irrespective of the exterior pressure about the fuse.

7. A time fuse having a vent from the interior to the exterior, incombination with a time powder-train, 'valve means in the fuse betweenthe vent and the powder-train and means for maintaining a closingpressure on p the valve means independent'othe atmospheric pressure.

8. In a time 'use the combination with a time powder train, of means foradjusting the time train and means in the `fuse for maintaining apredetermined pressure on the powder train irrespective of the pressuresexternal to the fuse.

9. A' time fuse having a. vent from the in-v

